Polymers made employing catalyst systems having bridging atom(s) of one or more carbon, silicon, germanium, phosphorous, or nitrogen atom(s) are known (U.S. Pat. No. 4,985,576, EPA 129368). Most typical are ethylene-bridged systems in which two carbon atoms link substituted or unsubstituted cyclopentadienyl or indenyl moieties. (U.S. Pat. No. 4,931,417; EPA 485,820; U.S. Pat. No. 5,017,714).
For example, Hoechst AG, of Germany, discloses carbon bridged indenyl catalyst components which are chiral and useful for the production of high molecular weight isotactic polypropylene ("IPP") (EPA 413,326; EPA 485,822; EPA 485,823; U.S. Pat. No. 4,769,510 and U.S. Pat. No. 5,145,819). EPA 485,821 discloses indenyl catalyst components bridged with carbon-silicon, germanium-silicon, or tin-silicon combination of atoms. These catalyst components are useful in the production of IPP having a melting point of about 150.degree. C. or greater.
Catalyst components having mono or diamido siladiyl bridging cyclopentadienyl groups are not well known. Jutzi, et al., disclosed in Chemical Ber, 1988, 121, 1299 preparation of a siladiyl-amine-bridge pentamethyl cyclopentadienyl derivative. However, this derivative is not a catalyst component, nor can it be converted to a cyclopentadienyl catalyst component since no transition metal is present.
It would be desirable to provide a novel catalyst component which can be useful for the polymerization of olefins or alpha-olefins wherein the catalyst component comprises mono- or diamido-siladiyl bridging atoms.